The invention relates to an aseptic filling machine for food, in which food is filled in containers of a deep-drawn bottom film and the container is sealed against a top film. The machine has storage rolls for the top and bottom film, with sterilizing devices for the films and a clean-air-area installed behind the sterilizing devices in which the food is filled in the containers formed from the bottom film which are closed and packaged hermetically and sterile with the top film.
With this kind of machinery, liquid and pastry products, especially for the food industry, are packed aseptically and sterile. The invention is particularly directed to the sterile packaging of foods such as coffee cream, pudding yoghurt and all kinds of fruit juices and similar products.
All known machines have basically the same construction. At first the film is drawn from a roll and inserted into the machine as bottom film. Before the film is inserted into the machine, it is cleaned and deionized and after the deionization it is inserted into a forming station where cup-shaped containers of this film are formed.
The film thus formed into cup-shaped containers is moved into a stetrile area where the food is filled into the containers under sterile conditions.
Furthermore, it is known to use a top film to close the filled containers. The top film is also cleaned and deionized and afterwards sealed against the containers filled with food.
With the machines known up to now there were problems with the sterilization of the top and bottom film as well as with the maintaining of sterile conditions in the clean area in which the product is filled.
In one known machine, the sterilization of top and bottom film is done chemically, for instance by leading the film through a solution of hydrogenperoxide. However, the disadvantage of this method of cleaning is the handling of this relatively dangerous and irritating chemical.
Furthermore, it is known to sterilize the top and bottom film by means of steam. The disadvantage of this known steam sterilization technique is that a discharge for the condensate has to be provided. Therefore a special film of high form-stability has to be used and this is a highly energy-consuming design because the sterilization has to be done at 140.degree. C.
Furthermore steam pressure containers have to be used for this purpose which have to be authorized for safety purposes by special authorities this results in high machine costs for this kind of steam sterilization.
Furthermore, it is known to use top and bottom films which are already aseptic, but this results in high film costs; this type of aseptic film has a protecting layer which has to be torn away and removed during the processing which results in increased refuse disposal.